HOW RELEVANT IS SECONDARY LEUKEMIA FOR INITIAL TREATMENT SELECTION INHODGKINS-DISEASE

Specific tools of decision analysis, a set of mathematical rules for s implifying complex decisions, were applied to evaluate the impact of s econdary leukaemia on the selection of initial treatment in Hodgkin's disease (HD). For this purpose, a combined 'expected utility' consider ing survival, relapse free survival, and secondary leukaemia was deter mined for different treatment strategies. Our analysis revealed that c onsiderations of secondary leukaemia for initial therapy should includ e the a priori estimation of all possible events which may occur after initial treatment, e.g, the probabilities of recurrence and success o f salvage therapy. In early and intermediate stage HD, for example, th e minimal risk of leukaemia after successful radiotherapy (RT) must be weighed against the increased risk after treatment failure and subseq uent salvage therapy. Thus, the difference of expected risk of leukaem ia between RT and combined modality treatment (CMT) is within 4% for H D, stage II B and near to 0% in stage III A. In advanced stage HD, the addition of RT to chemotherapy has no adverse effect on the expected utility of initial treatment. These conclusions are only marginally af fected by reported differences in rates of recurrence, salvage success , and secondary leukaemia. Subjective quality of life considerations, such as the latency period between treatment and leukaemia and patient s' attitudes towards the occurrence of leukaemia, did not significantl y affect expected utilities. In summary, our results strongly suggest that presently there is no sound basis for reducing the intensity of i nitial treatment in HD to avoid secondary leukaemia.